Abstract: A silicon nanosheet comprising a silicon atom layer formed by bonding two-dimensionally and periodically arranged silicon atoms to each other through an Si—Si bond. A nanosheet solution prepared by dispersing or suspending the silicon nanosheets in a solvent. A nanosheet-containing composite having the silicon nanosheets on the surface and/or in the interior of a substrate. A nanosheet aggregate formed by aggregating the silicon nanosheets. A process for producing a nanosheet solution comprising: an acid treatment step of bringing a layered silicon compound into contact with an aqueous acid solution to derive a siloxene compound; and an exfoliation step of adding the siloxene compound into a solvent containing a surfactant, shaking the mixture, and peeling off the siloxene compound.

Abstract: Disclosed are a porous material comprising particles without substantial fibrous structure and having pores, the pores having a mean pore diameter in a meson-pore region, sharp pore size distribution, and at least a part of the pores being connected three-dimensionally to form a three-dimensional network structure with random passages, the porous material preferably being of alumina and having a spongy structure or the porous material preferably being an aggregate of particles having an aspect ratio of 3 or less; a process of producing the porous material which includes a step of aging a system capable of becoming an oxide on thermal decomposition; a catalyst for exhaust gas purification having excellent NOx removal performance, high resistance against sulfur poisoning, and satisfactory high-temperature durability which comprises the porous material as a carrier having supported thereon a noble metal and an NOx storage component; and a method of exhaust gas purification using the catalyst.

Abstract: Disclosed are a porous material comprising particles without substantial fibrous structure and having pores, the pores having a mean pore diameter in a meson-pore region, sharp pore size distribution, and at least a part of the pores being connected three-dimensionally to form a three-dimensional network structure with random passages, the porous material preferably being of alumina and having a spongy structure or the porous material preferably being an aggregate of particles having an aspect ratio of 3 or less; a process of producing the porous material which includes a step of aging a system capable of becoming an oxide on thermal decomposition; a catalyst for exhaust gas purification having excellent NOx removal performance, high resistance against sulfur poisoning, and satisfactory high-temperature durability which comprises the porous material as a carrier having supported thereon a noble metal and an NOx storage component; and a method of exhaust gas purification using the catalyst.

Abstract: Disclosed are a porous material comprising particles without substantial fibrous structure and having pores, the pores having a mean pore diameter in a meso-pore region, sharp pore size distribution, and at least a part of the pores being connected three-dimensionally to form a three-dimensional network structure with random passages, the porous material preferably being of alumina and having a spongy structure or the porous material preferably being an aggregate of particles having an aspect ratio of 3 or less; a process of producing the porous material which includes a step of aging a system capable of becoming an oxide on thermal decomposition; a catalyst for exhaust gas purification having excellent NOx removal performance, high resistance against sulfur poisoning, and satisfactory high-temperature durability which comprises the porous material as a carrier having supported thereon a noble metal and an NOx storage component; and a method of exhaust gas purification using the catalyst.